Aromaticity in a Surface Deposited Cluster: Pd4_4 on TiO2_2 (110)

We report the presence of \sigma-aromaticity in a surface deposited cluster, Pd$_4$ on TiO$_2$ (110). In the gas phase, Pd$_4$ adopts a tetrahedral structure. However, surface binding promotes a flat, \sigma-aromatic cluster. This is the first time aromaticity is found in surface deposited clusters. Systems of this type emerge as a promising class of catalyst, and so realization of aromaticity in them may help to rationalize their reactivity and catalytic properties, as a function of cluster size and composition.Comment: 4 pages, 3 figure

Dietary Deficiency of Essential Amino Acids Rapidly Induces Cessation of the Rat Estrous Cycle

Reproductive functions are regulated by the sophisticated coordination between the neuronal and endocrine systems and are sustained by a proper nutritional environment. Female reproductive function is vulnerable to effects from dietary restrictions, suggesting a transient adaptation that prioritizes individual survival over reproduction until a possible future opportunity for satiation. This adaptation could also partially explain the existence of amenorrhea in women with anorexia nervosa. Because amino acid nutritional conditions other than caloric restriction uniquely alters amino acid metabolism and affect the hormonal levels of organisms, we hypothesized that the supply of essential amino acids in the diet plays a pivotal role in the maintenance of the female reproductive system. To test this hypothesis, we examined ovulatory cyclicity in female rats under diets that were deficient in threonine, lysine, tryptophan, methionine or valine. Ovulatory cyclicity was monitored by daily cytological evaluations of vaginal smears. After continuous feeding of the deficient diet, a persistent diestrus or anovulatory state was induced most quickly by the valine-deficient diet and most slowly by the lysine-deficient diet. A decline in the systemic insulin-like growth factor 1 level was associated with a dietary amino acid deficiency. Furthermore, a paired group of rats that were fed an isocaloric diet with balanced amino acids maintained normal estrous cyclicity. These disturbances of the estrous cycle by amino acid deficiency were quickly reversed by the consumption of a normal diet. The continuous anovulatory state in this study is not attributable to a decrease in caloric intake but to an imbalance in the dietary amino acid composition. With a shortage of well-balanced amino acid sources, reproduction becomes risky for both the mother and the fetus. It could be viewed as an adaptation to the diet, diverting resources away from reproduction and reallocating them to survival until well-balanced amino acid sources are found

Personalized peptide-based vaccination for treatment of colorectal cancer: rational and progress

Colorectal cancer (CRC) is one of the most common cancers globally and is associated with a high rate of morbidity and mortality. A large proportion of patients with early stage CRC who undergo conventional treatments develop local recurrence or distant metastasis and in this group of advanced disease, the survival rate is low. Furthermore there is often a poor response and/or toxicity associated with chemotherapy and chemo-resistance may limit continuing conventional treatment alone. Choosing novel and targeted therapeutic approaches based on clinicopathological and molecular features of tumors in combination with conventional therapeutic approach could be used to eradicate residual micrometastasis and therefore improve patient prognosis and also be used preventively. Peptide-based vaccination therapy is one class of cancer treatment that could be used to induce tumor-specific immune responses, through the recognition of specific antigen-derived peptides in tumor cells, and this has emerged as a promising anti-cancer therapeutic strategy. The aim of this review was to summarize the main findings of recent studies in exciting field of peptide-based vaccination therapy in CRC patients as a novel therapeutic approach in treatment of CRC